Erickson MCC™ Engine Technology

Erickson MCC™ Simulation (Click on Image Below) Exploded View of MCC™ Engine Erickson MCC™ Mechanism (Rear View)

This view of the MCC™ Engine shows its three moving parts which include the Orbiting Piston, CCM, and Crankshaft.   The MCC™ Engine is a twin combustion chamber engine that fires on the left and right side in the primary combustion chambers as illustrated above.  
   

The Erickson MCC™ Full Expansion engine is the first practical full expansion engine. True full expansion is achieved when gas expansion continues inside the mechanism to a final volume 3.5 times the original swept intake volume. This allows the gases inside the engine to reach atmospheric pressure. The full expansion process uses all the available energy to produce work. This results in a cool exhaust without any exhaust blow down noise.

The full expansion cycle variant of the MCC engine is illustrated in Figures 1 - 4. These views are referenced from the back of the engine and show a clockwise crankshaft rotation. The fuel air mixture is indicated by triangles and the expanding exhaust gas is indicated by squares. There are four variable volume chambers; A, B, C and D, formed within the Power Block by the Orbiting Piston (OP) and Combustion Chamber Member (CCM). The right combustion chamber A operates with the lower secondary expansion chamber B. Likewise, the left combustion chamber C operates with the upper secondary expansion chamber D. Since both pairs of chambers operate independent of each other, the engine is classified as a twin. Both pairs of chambers operate exactly the same so the operation of only one pair of chambers needs to be explained.

The engine's basic mode of operation is called Suction Induction Dual Expansion (SIDE). Figure 1 shows that induction of the fuel air mixture begins as the induction port opens. The suction is caused by the continued expansion of the gases to a point below atmospheric pressure. This is achieved by the dual expansion that is performed by chambers A and B by means of a transfer port in the CCM. The total expanded volume must be 3 to 3.5 times the initial compression volume of chamber A in order for the two chambers to reach atmospheric pressure. This happens at the point where chamber A has reached its maximum volume and chamber B has reached its one-half volume position, as depicted by Figure 1. As chamber B continues to expand, the pressure drops below atmospheric pressure. This causes the suction that pulls the fuel air mixture into chamber A as the exhaust gas products are pulled into chamber B ahead of it.

Fig 2.   Continue Expansion Induction

As chamber B reaches its maximum volume, as shown in Figure 2, it has pulled practically all of the exhaust products from chamber A into chamber B. At the same time, the exhaust gases in chamber A are replaced by a fresh new fuel air charge. Now the piston rapidly closes the induction port and the transfer port. Once both ports are closed, chamber A begins compression of the new charge.

Fig 3.   Compression, Exhaust, and Start of Primary Expansion

In Figure 3, the fuel air mixture is ignited slightly before top dead center. This begins the initial combustion and primary expansion in chamber A. At the same time, the exhaust gases in chamber B are pushed out of the engine through a port in the CCM and a port in the orbiting piston. Exhaust gases exit through the piston and then out the rear exhaust manifold. The exhaust is quiet and cool because most of the available thermal energy has been used to perform work within the engine.

It should be noted that the exhaust gas can be ejected at a high back pressure without affecting the induction process. If a conventional piston engine is subjected to any back pressure, the exhaust will begin to back up into the induction system which will result in reduced performance. The MCC full expansion engine pumps the exhaust gas out of the engine at a different time than when induction occurs. Therefore, the only performance loss is due to the amount of power required to pump the exhaust gas against the encountered back pressure. This gives the MCC engine the ability to eject exhaust gases through a small tube over long distances. This feature is not practical with the standard piston engine. 

Fig 4.  Exhaust Complete - Secondary Expansion in Process

Figure 4 illustrates the completion of the exhaust function and the beginning of the secondary expansion process in chamber B. This dual expansion process begins when the transfer port in the CCM is opened by the piston. Dual expansion pushes the piston in a clockwise direction as the CCM moves in an upward direction. Chambers A and B will expand until the pressure in the chambers falls below atmospheric pressure as illustrated in Figure 1.  As the CCM moves upward, it will open the induction port and a new cycle will begin.